This invention relates to a braided sleeve.
Braided sleeves are commonly used for mechanical, electrical, flame or thermal protection of elongate objects such as pipes or tubes or, more especially, wire bundles. Such sleeves are generally formed from yarns, each of which comprises a tow of relatively flexible filaments. For example the yarn may comprise staple or continuous filaments. Staple filaments are generally relatively short compared with the length of the yarns formed from them, which yarns are generally formed by spinning the filaments. Continuous filaments are generally of such length that they extend substantially throughout the length of yarns formed from them.
The material from which such braided sleeves are formed is generally selected from the group consisting of ceramic, quartz, glass, carbon and engineering plastics (such as for example nylons, polyamides, polyesters, etc.), and mixtures thereof. The construction of tows from such filaments will generally be selected according to the requirements of the application to which the sleeve is to be put. The number and diameter of the filaments in each tow, and the number of tows in the braid and the number of carriers on the braiding machine are factors which can be varied in order to change the flexibility of, and degree of protection afforded by the sleeve.
The use of a braided sleeve has the advantage that its transverse dimension can be varied by the application of longitudinal force or outward radial pressure, this being a unique feature of a braided structure. This feature requires that the yarns from which the sleeve is made are able to move relative to one another in a trellis sense, that is by changing the braid angle. This movement tends to cause the yarns to splay radially of the end of the sleeve so that the sleeve frays, and the requirement that the yarns be able to move relative to one another generally means that it is not possible to hem or otherwise to seal the end of the sleeve to prevent such fraying.